Method of and machine for applying metal spring covers



Nov. 20, 1934.

VJ..M. CHRISTMAN IETHOD OF AND MACHINE FOR APPLYING METAL SPRING COVERS 2 Sheets- 8h: 1

Filed July 14. 1930 Nov. 20, 1934. J. M. CHRISTMAN 1,981,090

METHOD OF AND MACHINE FOR APPLYING METAL SPRING COVERS Filed July 14, 1930 2 Sheets-Sheet 2 Patented Nov. 20, 1934 UNITED STATES PATENT OFFICE METHOD OF AND MACHINE FOR APPLYING METAL SPRING COVERS Application July 14, 1930, Serial No. 467,896

31 Claims.

This invention relates to a method .of and machine for applying covers to vehicle springs and more particularly for such a method and machine for closing and crimping the parts of sectional metal spring covers.

It is a general object of the present invention to provide a novel and improved method and apparatus for applying, closing, and crimping sectional metal spring covers.

More particularly it is an object of the inven tion to provide a method and apparatus wherein laminated vehicle springs are first loosely provided with metal cover sections and are then flexed into position within a fixture whereby the sections are clamped between the spring and fixture and are then subject to closing and crimping operations for tightly fitting and crimping the cover sections about the spring, after which the spring is finally released and ready for use.

An important feature of the invention resides in the manner of clamping the sections between an anvil or fixture and the spring whereby they are held and engaged with three faces ofthe spring and clamped against movement thereon so that their fourth side can be closed and crimped.

Another feature resides in providing a spring fixture equipped with means for holding the spring compressed so that the fixture and spring can be moved from station to station on the apparatus for closing and crimping the sections.

Another important feature of the invention resides in the actual closing and crimping apparatus as well as in the use of two sets of such apparatus to act in opposite directions and at different tEmes on the two ends of the spring.

Other and further features of the invention will be apparent from the accompanying drawings and following specification.

The invention has been shown, by way of example only, in the accompanying drawings and described in the following specification. But a single embod ment'of the invention is illustrated 7 herein, but it will be understood that it is subject to such changes and deviations from the original disclosure as fall within the scope of the appended claims without departing from the spirit of the invention.

In said drawings:

Figure 1 is a side elevation diagrammatically illustrating a machine for performing the various operations attendant upon the equipping of a vehicle with a sectional metal cover;

Figure 2 is an enlarged side elevation of the crimping apparatus showing a spring in position on a fixture ready to be operated on;

Figure 3 is a vertical section through a fixture with a spring applied and compressed thereontaken on line 3-3 of Figure 4;

Figure 4 is a transverse vertical section on line 4-4 of Figure 3; and

Figures 5, 6, 7, 8, and 9 are transverse sections somewhere between the center and end of the spring and fixture, for instance, on line 5-5 of Figure 3, and illustrating in sequence the steps of closing and crimping the spring covers.

The advantages of covering the laminated springs as used on automotive vehicles are well appreciated, and a discussion of the values or merits of such covers would be out or place here. However, it has been found that the most satisfactory form of cover is a metal one, and, in order that this may follow the fiexures of the spring, it is highly desirable that it be sectional. With such covers the greatest difficulty in their use arises in applying them to the springs with suflicient rapidity and accuracy to permit of rapid. production. Heretofore the covers have been applied, closed, and crimped by hand methods which not go only are not uniform and accurate but are extremely wasteful of time. The present invention contemplates a method of and apparatus for mechanically closing and crimping such spring covers.

While the invention is not restricted to any particular type of spring or cover, it has been illustrated here for the sake of convenience in connection with a conventional, laminated, semielliptical spring of the type most commonly in use on pleasure vehicles. The covers have been illustrated, for example, as formed from a series of telescopic sections bent up from thin sheet metal wherein each successively smaller section has its larger end overlapping the smaller end of the; next larger section, with the final small end '0;- the last section substantially abutting the spring eye. This effectively prevents longitudinal movement of the sections in respect to the spring, which in normal construction tapers almost uni- 10o formly from center to end sothat the final form of the covers is substantially that of along thin rectangular pyramid or wedge.

When applied initially to the spring, each cover section consists of a flat or substantially flat bottom portion adapted to engage the main leaf of the spring, two side portions to engage the edges of the spring leaves and of such length as to reach to the top leaf, and a fourth side at least partially open and adapted to be closed by two flaps which I together form ,the side and extend, across the top of the spring. These two flaps are provided with some form of tabs for crimping and interlocking.

When the section is closed, it forms a hollow tubular member substantially rectangular in crosssection, of uniform width but tapering slightly in thickness. Other forms of covers may be used wherein interlocking beads on adJacent sections prevent relative movement. In the operation of applying covers to springs, each leaf of the spring, before assembly, is dipped in a suitable lubricant, such, for instance, as a graphite grease, the leaves are then assembled, and again heavily coated with graphite grease.

. It may be mentioned here that, where metal spring covers are used, the conventional spring clips f r holding the leaves together on rebound are dis ensed with and their function performed by the covers. Following the coating with grease, the springs arevwrapped in a heavy grease impregnated fabric, such as canvas, which not only holds the leaves together until the covers are applied but retains the grease in contact with the springs and to a large extent excludes water and dirt although this function is primarily effected by the covers themselves. I

Referring 'now to the drawings, the spring is best seen in Figures 3 to 5, inclusive, as comprising a plurality of leaves or laminations 10, one of places.

which 11 is known as the main leaf and is on the concave side of the spring, extends for its full length, and is bent into eyes 12 and 13 at the ends. This main leaf has superposed on it a plurality of successively shorterleaves 10, each tapering from center to ends. For the sake of clearness, the

canvas wrapping has beenomitted in the drawings. The covers are not applied to the central portion 14, for that is adapted to be clamped to the'vehicle axle. v

Each cover is substantially of the form shown in section in Figure 5, where there is a fiat bottom 17 of sheet metal arranged to normally engage the fabric on the main leaf 11, the two sides 18 adapted to snugly engage the fabric on the edges of the leaves, and the top flaps 19 and 20 which are initially as wide open as that shown at 19. The fiap 20 has a bead 21 turned up at right angles thereto, and the flap 19 has the channel shaped edge 22 adapted to engage over the bead 21 when the two parts are folded down in the order shown.

After the spring has been covered with its fabric wrapping, the spring cover sections are applied by hand and loosely positioned in the proper If it is found necessary, they may be temporarilyheld in position by clamps, such, for

' instance, as battery clips connected between the g parts 21. and 22. These cover sections are of sp'i'ingy metal and can easily be sprung into place.

When both .ends of the spring have been equipped with their complement of cover sections, the spring is mounted'on the fixture 25 shown best in Figures 2 and 3. As shown in the drawings, this fixture is substantially formed from a single block of metal although it could be as readily fabricated from parts. This heavy block of metal has a fiat base. 26 and is of substantially the length of the spring which it is to accommodate and considerably wider. Longitudinally of the block the top is providedwith a channel 27 of such width as tojust snugly engage the side members 18 of the spring sections and throughout its length of Just the proper depth to fully accommod'ate the spring and to leave the thickness of the metal of the flaps 19 and 20 exp s d. This 31 to hold it in position.

means that the groove or channel tapers-in depth to conform to the thickness of the spring. The bottom wall 29 of the channel is convex,'as seen in Figure 3, but of greater radius or of less curvature than that of the main leaf of the spring in its normal condition.

One end of the block has an extension 30 of the channel forming a depression to receive the spring eye 12 and having an overhanging portion The spring with its complement of cover sections has its eye 12 fitted in this portion 30 and is swung down to a position 1 above the channel when its other eye 13 is attached by means of a pin 34 to the ends of the links 35 which are pivoted at 36 to the fixture block. This places the-spring in the position shown in dotted lines in Figure 3.

The fixture block is adapted to be positioned on and. travel longitudinally of the runway 40 shown in Figure l as supported on suitable posts 42 and columns'43 and 44. This runway is in the form of a track to guide the fixture as it moves from station to station along the runway. At

the stations A, B, and C, the spring is lubricated,

wrapped, and has the cover sections loosely applied thereto and is mounted in the position shown in thedotted lines in Figure 3.

It is then moved to station D, where its center comes beneath the ram 45 of the hydraulic press 46 where pressure is applied to flex the spring until its bottom leaf tightly presses the bottom walls 17 of the spring covers into engagement with the bottom of the channel 29 in the fixture.

in Figure 2, the side walls 50 of the channel in the fixture are cut away in the center where no covers are applied to the spring, and bifurcated yoke blocks 52 are attached in their stead, which mount the pivots 53 for the hook members 49. Depending extensions 54 on the hook members are provided with blocks 55 which fit between the forks 56 of nuts threaded on the transverse bolts 57 which pass through openings in the block and are provided with the knurled operating heads 58. The threads in the two nuts on each bolt are reversed; that is, one is left and one right so that, when the bolt is turned in one direction, the hooks are advanced over the top leaf and vice versa.

As soon as the hooks have been positioned over the top leaf to hold the spring in its compressed position, the pressure from the ram may be released, and the fixture is moved to station E and has applied behind it a stop 60 against which it abuts.

It will be noted that, in flexing the spring to clamp the cover sections in position, it has been bent to such a position thatthe upper surfaces of the two ends are almost fiat but at an angle to each other. Mounted above the station E is Each carrier has a bifurcated lower end accommodating the upper portion of a roller- 68 pivoted at 69 and adapted to cooperate with the flaps on the spring covers to close and crimp them. The carriage is adapted for movement from the end of the spring to thelarger part under the action of a cable 70 secured to the eye '71 on the carriage, passing around the pulley 72, mounted on the drive member 73, with the upper reach 74 of the cable returning above to the idler pulley 75 at the lower end of the track. The far end of the cable is attached to the eye '16 at the opposite end of the carriage.

In Figure 5 is seen the roller 68:: which first engages the cover sections successively, folding down the flaps 20 thereon tightly into engage ment with the top leaf of the spring. Following this is the roller 682) which not only holds the flaps 20 in position but rolls down the flaps 19 so that their channel portions 22 interlock with the beads 21 on the fiaps 20. A central groove in this roller with the tapered edges 81 serves to close the channels 22 about the beads 21. As seen in Figure '7, the next roller, 68c, is somewhat like 68b but is conical in shape and provides an initial bend or tilt to the interlocked channels and beads. This is followed by the roller 68d which further turns the crimped parts down and over the flaps 20 and finaily the stepped roller 68c, shown in Figure 9, which mashes the now complete crimps as flat as possible to the position shown at 82, which completes the closing and crimping operations.

With the carriage to the left in Figure 2, the fixture is then moved to station F. Here the same type of operation can take place either by moving the carriage 83 from right to left, or, as shown, the fixture can be first moved slightly beyond F and the carriage 83 moved to the left, the fixture returned, the stop 84 put in position, and the carriage moved from left to right again, acting from the small to the large part of the spring as it did at station E. Here is completed the crimping of the second half of the spring cover, and the fixture can then be moved, by releasing the stop 84, to station G, where it is put beneath a second ram 85 to hold it while the hooks 48 are released. Then the pressure on the ram can be released, the fixture moved from beneath it, and the spring complete with its cover lifted out ready to be applied to the vehicle.

The whole operation is accomplished in a very short period of time and substantially entirely mechanically, and the crimping is effected with greater uniformity, ensuring a tight fit for all of the covers and an accurate and 88-. cure crimping. It will be appreciated that various forms of rollers deviating some from those shown may be used to actually produce the closing and crimping, and it is to be understood that in the following claims the expression "closing and crimping means-is intended to include" not only the types of rollers shown but other rollers or even slides or folding means for effecting crimping.-

'Iclaimi 1. The method of applying metal covers tolaminated automobile springs comprising, placing a plurality of sections of spring cover on a spring, flexing the spring to hold the sections between the spring and an anvil and the indi-- vidual leaves in close proximity throughout their length and securing the sections tightly onto the spring. l

2. The method of applying metal spring covers to laminated vehicle springs comprising, engaging a plurality of sections of spring cover on a spring with open sides at the convex side of the spring, flexing said spring to clamp said sections against an anvil and to hold the leaves inengagement throughout their length, closing the open sides-of the cover sections and securing them shut.

3. The method of applying metal spring cov- Y ers to laminated vehicle springs comprising assembling a plurality of sections of spring cover.

along the spring with open sides in alignment, flexing said spring to clamp one side of each section against an anvil, and successively closing and securing the sections about the spring.

4. The method of applying metal spring covers to laminated vehicle springs comprising assembling a plurality of sections of spring cover alon the spring with open sides in alignment, flexing said spring to clamp one side of each section against an anvil, and successively engaging a plurality of closing and crimping tools with each section in the order of their arrangement on the spring. i

5. The method of applying metal spring covers to laminated vehicle springs, comprising assembling a plurality of telescoping sections along the spring" with sides and bottoms respectively engaging the sides and main leaf of the spring and with flaps open at the convex side of the spring, reducing the curvature of the spring to clamp the sections between the main leaf and an anvil and closing and securing said fiaps about the spring successively from end to center of the spring.

6. The method of applying metal spring covers to laminated vehicle springs, comprising assembling a plurality of telescoping sections alon the springwith sides and'bottoms respectively engaging the sides and main leaf of the spring and with flaps open at the convex side of the spring, mounting said spring in a fixture, compressing the spring to clamp the sections between the spring and fixture, moving said fixture beneath a roller assembly and moving said as-- sembling a plurality of open cover sections along the spring, mounting the spring in a fixture, com- 1 pressing the spring, clamping the sections between the spring and fixture, moving a plurality of rollers successively over each section in the order of its position on the spring to close and fasten the sections ontothe spring and releasinc the spring from the fixture.

'8. The method of applying metal spring covers to laminated vehicle springs comprising assembling a plurality of cover sections along the spring with sides and bottoms respectively engaging the sides and main leaf of the spring and with flaps open at the side of the spring opposite the main leaf, mounting said spring in a fixture, clamping the cover sections between the spring and fixture to hold them in position on the spring, relatively moving the fixture and a crimping mechanism and causing said mechanism to successively close and crimp the sections tightly about the spring.

9. The method of applying metal spring covers to laminated vehicle springs comprising, assembling a plurality of cover sections along the spring with sides and bottoms respectively en-- gaging the sides and main leaf of the spring and with fiaps open at the side of the spring opposite the main leaf, mounting said spring in a fixture, engaging three sides of each section to hold it against the spring,'pressing the spring strongly toward said fixture to clamp the sections in position, moving the fixture beneath a slide inclined substantially parallel to one portion of the spring and moving a closing and crimping assembly along said slide and in engagement with said sections successively from end to end of said portion. a

10. A machine for applying metal spring covers to laminated vehicle springs comprising in combination, a runway, a fixture movable along said runway and adapted to hold a spring with cover sections applied thereto, a compression device to fiex the spring on the fixture, a carriage guide above said runway, a stop beneath said guide for said fixture, a carriage movable on said guide and crimping means for said cover sections on said carriage.

11-. A machine for applying metal spring covers to laminated vehicle springs comprising, in combination, a runway, a fixture movable along said runway, means on said fixtureto receive a spring and hold it with cover sections loosely applied thereto, means adjacent a portion of said runway to compress the spring and clamp the cover sections between it and the fixture, means on said fixture to' hold the spring compressed, a carriage slide mounted above a portion of said runway, a carriage movable along said slide, closing and crimping means on said carriage and means to move the carriage along with said closing and crimping means engaging said cover sections.

12. A machine for applying metal spring cov-* ers to laminated vehicle springs comprising, in combination, a runway having a plurality of stations thereon, a fixture movable along said run: way to said stations successively, means on said fixture to receive a spring and hold it with cover sections loosely applied thereto, means at one of said stations to compress said spring to clamp the sections between it and the fixture, means on the fixture to secure the spring compressed, closing and crimping means for the sections-on one end of the spring at the next station, closing and crimping means at another station for the remaining cover sections and means at a further station to release said spring from compression.

13. The method of applying metal spring covers to laminated vehicle springs comprising mounting the spring on a fixture, loosely positioning open cover sections thereon, moving the fixture to a station, compressing the spring to engage the sections against the fixture, clamping the compressed spring to the fixture, moving the fixture and spring to another station, closing and crimping the sections, moving the spring and fixture to another station and releasing the compression.

14. The method of applying metal spring covers to laminated vehicle springs comprising mounting the spring on a fixture, loosely positioning open cover sections thereon, moving the fixture to a station, compressing the spring to engage the sections against the fixture, clamping the compressed spring to the fixture, moving the fixture and spring to another station, securing the fixture in position, moving closing and crimping means along a track substantially parallel to one end of the spring and in engagement with the cover sections, moving the spring and fixture to an adjacent station, moving other closing and crimping means along a track sub-' stantially parallel to the other end of the spring and in engagement with the cover sections, moving the spring and. fixture to a final station an releasing the compression.

15. A machine for applying metal spring covers to laminated vehicle springs comprising, in combination, a runway having a plurality oi stations thereon, a fixture movable from station to station along said runway, stops to maintain the fixture in position at certain stations, means on said fixture to receive and hold a spring with open cover sections thereon, means at one 0! said stations to fiex the spring to clamp the sections between it and the fixture, means on the fixture to clamp the spring in its compressed position, acarriage at the next station movable in a plane substantially parallel to the facing surface :of the spring, resiliently mounted folding and crimping means onsaid carriage and means to move said carriage to engage the folding and crimping means with the cover sections successively.

16. Mechanism for closing and crimping sectional metal'spring cover mounted on a laminated vehicle spring secured in a fixture, comprising, in combination, a track beneath which the fixture can be secured, a carriage slidable along said track, a plurality of rollers resiliently mounted on said carriage in alignment with its direction of motion, each roller being adapted to perform a step inflthe closing and crimping of of a spring and 01' other than the normal curvature oi the spring, sides projecting. above said surface to substantially the height of the spring and means to secure a spring thereon.

1 8. A fixture for holding a vehicle spring with metal cover sections loosely applied thereto comprising a block having a channel of the width or the spring and covers and of a depth varying to conform to the spring thickness, the bottom wall of said channel being curved to conform to the main leaf of the spring when fiexed, means on said block to hold one spring eye and means to pivotally link the other spring eye to the block.

19. A fixture for holding a vehicle spring with metal cover sections loosely applied thereto comprising a block having a channel of the width 0! the spring and covers and of a depth varying to .conform to the spring thickness, the bottom wall metal cover sections loosely applied thereto comprising a block having a channel of the width of the spring and covers and of a depth varying to conform to the spring thickness, the bottom wall of said channel being curved to conform to the main leaf of the spring when flexed, means on said block to hold one spring eye, means to pivotally link the other spring eye to the block and means on said block for clamping a spring in said channel when it is flexed to engage the bottom wall thereof.

21. The method of applying metal spring covers to laminated vehicle springs comprising engaging a plurality of sections of spring cover on a spring with open sides in alignment, holding the sides opposite the open sides against the spring, closing the open sides of the cover sections and interlocking them.

22. The method of applying metal spring covers to laminated vehicle springs comprising engaging a plurality of sections of spring cover on a spring with open sides in alignment, pressing the lamine of the spring together, using the said pressing effort to clamp one side of each of the cover sections between the spring and an anvil and successively closing and fastening said sections.

23. In a device for applying a cover to a vehicle spring, means for forming the cover about three sides of the spring with its marginal edge por-' tions interlocked at the fourth side, means for clinching the interlocked marginal edge portions, and means for striking the clinched edge portions over to form a seam.

24. In a machine for applying a cover to a vehicle spring, a spring support, means for securing a spring to said support, means whereby a cover is formed about the spring as it is secured to the support with its marginal edge portions in juxtaposition, and means for forming a seam of said cover marginal edge portions to lock the same on the spring.

25. The hereindescribed method of shrouding a vehicle spring with a metal cover which consists in compressing the spring and simultane ously locking. the cover about the spring, in locking the spring with the cover formed thereabout in its compressed state, in forming a seam at the marginal edges of the cover to lock the sameon the spring, and inreleasing the spring.

26. In a device for applying a cover to 9. vehicle spring, a spring support having a channel above which an unformed cover is adapted to be positioned and into which the spring is movable, and means for, moving the spring into said channel whereby the cover is formed about the sprin as it is moved into the channel.

27. The method of applying metal spring covers to semi-elliptical vehicle leaf springs which comprises flexing the spring toward straightened position, forming the cover about three sides of the spring with its marginal edge portions extending over the fourth side, uniting the marginal portions while the spring is thus flexed, and thereafter releasing the spring.

28. The method of applying metal spring covers to semi-elliptical vehicle leaf springs which comprises flexing the spring toward straightened position, forming a series of cover sections embracing three sides of the spring with flanged edge portions extending over the fourth side, and with the ends of adjacent sections overlapping, permanently uniting the flanges of said sections longitudinally of the spring, and-thereafter releasing the spring.

29: In a device for applying a cover to a vehicle spring, a support for the coverfmeans for moving the spring toward the support, means whereby the cover is formed about the spring as it is moved,

with its marginal edge portions in juxtaposition, and means for forming the seam of said marginal edge portions.

30. Apparatus for applying spring covers to semi-elliptical vehicle leaf springs, said covers having a central portion to engage one of the horizontal surfaces of the spring and side portions to engage the vertical sides of the spring provided with flanged edge portions to engage the other horizontal side of the spring, comprising a cradle having members flexibly to engage and support the ends of the spring, power applying means to engage the central portion of the spring operable in cooperation with said end-engaging means to flex the spring toward straightened po-' sition, means for forcing side portions of the cover against the sides of the spring; and means for uniting the flanged edge portions of the cover while the spring remains in flexed position.

31. Apparatus for applying spring covers to semi-elliptical vehicle leaf springs, said covers having a central portion to engage one of the horizontal surfaces of the spring and side portions to engage the vertical sides of the spring provided with flanged edge portions to engage the other horizontal side of the spring, comprising a cradle having members flexibly to engage and support the ends of the spring, power applying means to engage the central portion of the spring operable in cooperation with said endengaging means to flex the spring toward straightened position, means for forcing side portions of the cover against the sides of the spring, and means for permanently interlocking the flanged portions of the edge of the cover while the spring remains in flexed position.

Joan M. cmusman.

CERTIFICATE OF CORRECTION.

Patent No. l,98l,090. November 20, 1934'.

JOHN M. CHRISTMAN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring Correction as follows: Page 5, line 45, claim 25, for "locking" read forming; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of'the case in the Patent Office.

Signed and sealed this 8th day of January, A. D. 1935.

Leslie Frazer (Seal) Acting Commissioner of Patents. 

